Sixth slice of T-99. Long-lived event subscription path, the second
half of D-6.
Wire shape:
- Client sends `{cmd:"tail", args:{flags:{events:true, filter:X}}}`.
- Server responds with `{ok:true, data:{streaming:true, filter:X}}`.
- Server pushes `{type:"event", subsystem, kind, ts, data}` lines
until the client closes.
Server (lib/src/ipc/server.dart):
- Takes a DaemonBus, subscribes to DaemonEvent on start.
- Per-subsystem ring buffer (replayDepth=16 per D-6) populated on
every emit.
- `tail --events` connection: send ack, replay matching events from
ring, register the client for future fanout.
- _argv envelope now unwrapped at the server layer so the streaming
check sees the inner `tail` cmd (not just `_argv`).
- Broken subscriber writes drop the subscriber cleanly; the bus
doesn't block on a stalled client.
Client (native/clide-cli/clide.c):
- Sniffs `data.streaming:true` in the ack. If set, loops reading
JSON-line events to stdout (with fflush per line) until EOF.
Tests:
- test/ipc/server_streaming_test.dart — 8 cases covering ack shape,
filter, replay buffer (size + ordering), multi-subscriber fanout,
broken-subscriber cleanup.
- test/cli/clide_cli_e2e_test.dart gets a tail --events test that
spawns the C client, emits two events on the bus, asserts they
print on stdout.
T-99 children remaining: T-130 (MCP), T-131 (wrap-up).
Co-Authored-By: Claude <noreply@anthropic.com>